In a conventional electrophotographic image forming device, a blade member serving as a cleaning blade has been disposed around a photoreceptor, a blade portion of the blade member has been in sliding contact with the photoreceptor, and thus residual toner remaining on the surface of the photoreceptor has been removed by scraping off. For the material of the blade portion, a flexible and relatively inexpensive polyurethane rubber is generally used.
A polyurethane rubber generally has a high friction coefficient. Therefore, a surface treatment liquid including an isocyanate compound and a polymerization catalyst such as a quaternary ammonium salt or a carboxylic acid salt is impregnated into a blade portion made of a polyurethane rubber, and thereafter the impregnated isocyanate compound is heated and cured to thereby form a cured layer for an increase in surface hardness (see Patent Document 1).